The carpet tile is typically produced by coating the back surface of a carpet material having a primary backing sheet having a fibrous wear surface with one or more coatings of a polymeric composition. The polymeric composition may contain one or two sheets of stabilizing sheet material, such as glass fiber material such as tissue or scrim, and may also contain a secondary backing sheet on the back surface of the carpet tile. Generally, carpet tile is produced by either back coating the primary backing sheet with a PVC plastisol composition or in a different technique with a hot melt composition, such as a bitumen or an atactic polypropylene or bitumen-modified hot melt compositions (see U.S. Pat. No. 4,242,393, issued Dec. 30, 1980 hereby incorporated by reference in its entirety).
The technique of producing carpet tiles employing PVC plastisol is a different process in that PVC plastisol, on heating, gels and fuses, while carpet tile produced through the employment of hot melt composition provides for the heating of hot the melt composition to form a liquid hot melt composition, at least to form a tacky surface, and after contacting the fibrous backing sheet with the hot melt composition, controlled cooling. A typical method of producing carpet tile employing hot melt compositions, such as a bitumen composition, wherein the back surface of the carpet material is laid on to a precoated layer of hot melt bitumen composition is described, for example, in U.S. Pat. No. 4,582,544, issued Apr. 15, 1986, hereby incorporated by reference in its entirety. After coating of the carpet material, the carpet material is typically cut into carpet tile, generally 18 by 18 inches in the United States or 50 by 50 centimeters for the European market.
In carpet tile, it is desirable to provide a carpet tile which has good dimensional stabilities, good lay flat characteristics and further which carpet tile may be produced in an in-line production method.